Add Subtitles to Video Online for Free
Add subtitles to video using an SRT, VTT or ASS file. Download an MP4 with a text track that viewers can turn on or off in a compatible player.
How to add subtitles to video as a selectable track
- Select the video and its matching SRT, VTT or ASS subtitle file.
- Export an MP4 with a selectable subtitle track.
- Open the MP4 in a player, enable subtitles and check a line against the dialogue.
Move through a 12-second subtitle track
- 00:02–00:04
- Open the settings menu.
- 00:05–00:08
- Choose the display language.
- 00:09–00:12
- Save your changes.
Choose an SRT, WebVTT or ASS file for this cut
Select a playable video and a timed subtitle file for the same cut. The video supplies the picture and any readable audio, while the second file supplies the words and the times at which they appear. You can add subtitles to video with SRT, WebVTT or ASS input. If all you have is a recording of the conversation, transcribe it and time the lines first. The tool reads captions from the second file. A plain transcript still needs start and end times for each line. Changing its filename to end in .srt leaves those times missing.
Look at the first few entries in the subtitle file. Check the language, an early line of dialogue, and the time at which it should appear. If the movie includes a different opening logo or has been trimmed since the captions were created, the file with the same title may belong to another edit. Compare a line after an identifiable cut as well. Matching filenames make it easier to organize your material but do not synchronize two files.
How to show or hide the captions in the saved MP4
The exported MP4 carries the subtitles as a separate stream of timed text. A supporting player can show the picture without captions and enable the track when requested. The export takes its subtitle stream from the file you select under Subtitle file. Existing selectable subtitle tracks in the source movie are left out of this copy. The first frame of the video will not necessarily show any lettering. The track must be enabled, and playback must reach a time covered by a caption.
When you add subtitles to video this way, the text is not drawn into every frame. A player, presentation app or website that ignores embedded tracks may show the picture without offering a captions menu. If a publisher asks for a separate caption file, keep your original SRT or WebVTT and submit it in the requested field. If the requirement is for lettering that stays visible even without caption support, it calls for a burned-in version made in an editor that renders text onto the image.
How to check sync after you add subtitles to video
Play the result from just before the first spoken sentence. Then jump to an exchange in the middle and let it play through a change of speaker. Near the end, compare the last complete sentence with its caption. If every line is early or late by roughly the same amount, check for a missing countdown, title card or stretch of silence at the start of one version. Correct the times in the subtitle file before exporting again.
If the first scene matches but a later one is wrong, look for a missing scene, an extra shot or another edit between the two points. A single time shift cannot compensate for a removed passage partway through a movie. Before you add subtitles to video for delivery, make sure the source file runs to the same ending as the version used to prepare the captions.
What happens to subtitle styling and layout?
The tool converts the selected file to an MP4 text subtitle track. Players decide how to display that track, including some aspects of the font, text size and background. ASS subtitles may use precise positions, colored words or complex effects to give text a particular role in the scene. Keep the ASS source if that styling matters. Check a styled passage on the intended device before assuming that every aspect of the original layout survived.
Line length matters for viewers on small screens. Find the longest caption in a busy scene, then read it while watching the picture at normal speed. If a line wraps over an important detail, edit the wording or line breaks in the subtitle file and export a fresh copy. If two captions appear at once, make sure the reader can tell who is speaking even when the player places both at its usual caption position.
Questions about how to add subtitles to video
Can I add subtitles to video in more than one language?
The form accepts one subtitle file per export. For separate language versions, start again from the original movie, select the second language file and save the output with a distinct name. Creating one movie with a menu containing several new languages requires an editor that supports adding and labeling multiple subtitle streams.
Can I add subtitles to video without replacing the sound?
The movie supplies its own audio tracks when present. Captions do not generate narration or replace recorded speech. Listen to a known spoken line in the exported file with subtitles switched off, then enable them and check the same line. A silent source can still carry text captions, but it will not acquire a voice track from the words.
Can I add subtitles to video from a written translation?
Yes, if the translation is saved in a supported timed subtitle format. Keep the start and end of each cue aligned with the scene it describes. A translation may take more space on screen than the original, so check wrapping and reading time rather than comparing only the number of lines in the editor.
Why does my exported MP4 show two sets of subtitles?
Switch the selectable track off and watch the same moment again. If one set remains visible, it may already be drawn into the original picture, or the player may be loading another caption file from the folder. Open the original movie in a folder without external subtitles to distinguish those possibilities before adding a new track.